Restore content type from filename extension fallback

application/application.go

@@ -14,7 +14,6 @@ import (
 	"time"
 
 	"github.com/h2non/filetype"
-	"github.com/h2non/filetype/types"
 	"github.com/sirupsen/logrus"
 	log "github.com/sirupsen/logrus"
 
@@ -559,6 +558,8 @@ func (a *Application) PlayableMediaType(filename string) bool {
 func (a *Application) possibleContentType(filename string) (string, error) {
 	//If filename is an URL returns the content-type from the HEAD response headers
 	//Otherwise returns the content-type thanks to filetype package
+	var contentType string
+
 	if strings.Contains(filename, "://") {
 		req, err := http.NewRequest("HEAD", filename, nil)
 		if err != nil {
@@ -569,17 +570,49 @@ func (a *Application) possibleContentType(filename string) (string, error) {
 		if err != nil {
 			return "", errors.Wrap(err, "do request failed")
 		}
-		return res.Header.Get("Content-Type"), nil
+		contentType = res.Header.Get("Content-Type")
 	} else {
 		match, err := filetype.MatchFile(filename)
 		if err != nil {
 			return "", errors.Wrap(err, "match failed")
 		}
-		if match.MIME == types.Unknown.MIME {
-			return "", errors.Wrap(err, "unknown content-type")
+		contentType = match.MIME.Value
+	}
+	if contentType == "" {
+		if strings.Contains(filename, "://") && strings.Contains(filename, "?") {
+			parts := strings.Split(filename, "?")
+			filename = parts[0]
+		}
+
+		// https://developers.google.com/cast/docs/media
+		switch ext := strings.ToLower(path.Ext(filename)); ext {
+		case ".jpg", ".jpeg":
+			return "image/jpeg", nil
+		case ".gif":
+			return "image/gif", nil
+		case ".bmp":
+			return "image/bmp", nil
+		case ".png":
+			return "image/png", nil
+		case ".webp":
+			return "image/webp", nil
+		case ".mp4", ".m4a", ".m4p":
+			return "video/mp4", nil
+		case ".webm":
+			return "video/webm", nil
+		case ".mp3":
+			return "audio/mp3", nil
+		case ".flac":
+			return "audio/flac", nil
+		case ".wav":
+			return "audio/wav", nil
+		case ".m3u8":
+			return "application/x-mpegURL", nil
+		default:
+			return "", fmt.Errorf("unknown file extension %q", ext)
 		}
-		return match.MIME.Value, nil
 	}
+	return contentType, nil
 }
 
 func (a *Application) knownFileType(filename string) bool {